Candidate. This is a term which describes someone at any stage in the process of running for a public office. I believe that this word should be avoided if a person may be classified into one of the following categories.

Aspirant. Someone who is considering a campaign or has started the process of filing but has not filed the paperwork to appear on the ballot.

Contender. A contender is someone who has filed for the office and will appear on the ballot for the nomination (or for the first primary of nonpartisan races).

Nominee. A person who has won the nomination of a ballot-listed party or who will appear on the ballot as a third-party candidate.

This came up because someone I am familiar with (not Drew Pritt) wants to be called a "candidate" even though he did not gain ballot status. Where he lives, he needs to pay a fee to appear on the ballot - not like here in Pennsylvania, where an enormous number of signatures is required.